This invention relates to a nuclear reactor. In more detail, the invention relates to a reactor which is useful for breeding uranium-233 for use in a light-water breeder reactor.
The design of light-water reactors capable of self-sustained breeding has been extensively studied at Bettis Atomic Power Laboratory. These designs all include a heterogeneous array of rods fueled with (U.sup.233, Th)O.sub.2 pellets with a moderator and coolant of light water. The designs also have as a common feature the use of a movable fuel region coupled with some form of axial fuel variation to attain reactivity control. One such design is described in detail in patent application Ser. No. 461,475, filed Apr. 16, 1974, now U.S. Pat. No. 3,957,575.
Before any large-scale development of (U.sup.233, Th)O.sub.2 reactors can occur, it is necessary to develop an efficient means of obtaining large quantities of the fissile isotope U.sup.233. The only method by which U.sup.233 can be obtained in quantity is by the conversion of Th.sup.232 to U.sup.233. This requires the development of an efficient reactor which is fueled with available fuel and in which conversion of Th.sup.232 to U.sup.233 can be carried out. One such reactor which has been proposed is a reactor which uses only plutonium fissile fuel but operation of such a reactor is totally dependent on fissile fuel which must also be produced in a reactor. Another such reactor uses U.sup.235 as fuel with a low-cost diluent such as ZrO.sub.2 but such a reactor has a low thorium conversion ratio. Still another such reactor forms the subject matter of the present application.